1. Write a note on Thermal Pollution.
Aris. There is use of water for cooling of various industries units. In addition water is used as coolant in Electric power instruments and Nuclear power station. Such hot water of these plants are further added into their sources to enhance the water temperature. Aquatic plants and animals die due to sudden increases in temperature as well as increases in rate of respiration in aquatic plants.
2. Write an essay on Soil Pollution.
Ans. It is alteration in soil caused by removal or addition of substances and factors which decreases its productivity, quality of plants and ground water. Negative soil pollution is reduction in soil productivity due to erosion and over-use. Positive soil pollution is due to addition of undesirable substances which also reduces soil productivity. Pesticides and fertilisers are the two types of agrochemicals working as undesirable substances.
3. Write a note on Organic farming.
Ans. The technique of agriculture in which there is minimum use of chemical fertilizers, pesticides and other chemicals but use of organic matters are called organic farming. In such type of agriculture wastes from plants, faecesurine of animals, agricultural wastes, etc. are used to enhance the soil fertility. In which there is maximum use of resources to increase the productivity.
4. Write a note on Ozone depletion.
Ans. Various ultraviolet rays of sunlight are harmful to organisms from which Ozone layer protects our life. This Ozone layer is situated in our atmosphere above 16-50 km and works as protective coat. Due to this layer ultraviolet rays do not reach directly on earth surface. But some chemicals like Fluorocarbon (FC), Chlorofluoro carbon (CFC), etc which are useful in our modern life activities react with ozone and make depletion. This depletion is in the form of hole, so called ‘Ozone hole’. Ultraviolet rays pass on earth surface through these ozone holes and results into harmful effects on organisms.
5. Write a note on Global warming & its effect.
Ans. When increase in earth temperature is considered worldwide, then this is called Global warming. It occurs when CO, and other air pollutants collect in the atmosphere and absorb sunlight and solar radiations.
It can long term effect on threatening of life as well as rise in sea level alongwith submerging of various islands & near by town/cities of seas.
6. Mention Natural air pollutants and its types.
Ans. Toxic gases errupted from volcanoes, dust particles, smokes etc. are the main natural air-pollutants pollengrains spreeding in atmosphere, extracted in atmosphere.
Two categories of Natural air-pollutants are mainly-
(i) Primary pollutants: They come into atmosphere directly from various sources. e.g. SO₂, CO₂, oxides of Nitrogen etc.
(ii) Secondary pollutants: Such pollutants are produced by the reaction of primary pollutants and common compounds. located in atmosphere, e.g. Peroxy Acetyl Nitrate (PAN), Smog, etc.
7. What are electronic wastes? Give suitable examples.
Ans. They are irrepariable computers, mobiles and other electronic goods often called e-wastes. They are generally sent to developing countries like India, China & Pakistan for extraction of metals like copper, iron, silicon, nickel and gold through recycling. Waste electrical goods are similarly recycled but some of them like old batteries are quite hazardous to handle. [1]
Developed countries enforced strict environmental laws in 1980. This pushed up the cost of handling and treatment of hazardous wastes. A scientific method of treating e-wastes in an environment friendly manner has been developed. It is called evences.
9. Write a note on disposal of plastic wastes.
Ans. Ahmad Khan of Bangalore was a famous businessman of plastic bag manufacturing field who invented an effective method for the disposal of plastic wastes. Mr. Khan had a plastic business for long time. He prepared a fine powder of polyblend by recycling of plastic wastes. Such powder was used for making road surface by mixing in bitumen. For this, he took help and support of R.V. Engineering College & Bangalore city corporation. By this technique the water repellant properties of constructed road increases three times more. Hence, by the invention of polyblend and its application, the disposal of plastic wastes is possible a lot .
10. What do you understand by ex situ conservation?
Ans. In this approach, threatened animals and plants are taken out from their natural habitat and placed in special setting where they can be projected and given special care. Zoological parks, botanical gardens and wildlife safari parks serve this purpose. There are many animals that have become extinct in the wild but continue to be maintained in zoological parks. In recent years ex situ conservation has advanced beyond keeping threatened species in enclosures. Now gametes of threatened species can be preserved in variable and fertile condition for long periods using cryopreservation techniques, eggs can be fertilized in vitro and plants can be propagated using tissue culture methods.
